关键词: 二氧化锰阴极材料, Ag-TiO₂, 修饰, 电化学性能

Abstract:

 The silver-titanium dioxide  co-modified manganese dioxide (Ag-TiO₂-MnO₂) cathode material was prepared through high temperature solid state reaction. The microstructure, phase composition and electrochemical performance of the prepared samples were characterized by X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectroscopy (XPS), Energy-dispersive X-ray spectroscopy (EDS), Cyclic voltammetry (CV), galvanostatic discharge and electrochemical impedance spectroscopy (EIS). Results showed that the unmodified and Ag-TiO₂ modified MnO₂ samples both exhibited β-MnO₂ structurebut with different morphologies. The EDS mapping results revealed that Ag was uniformly dispersed on the surface of manganese dioxide, while Ti was relatively non-uniform in the Ag-TiO₂-MnO₂ sample. The modified samples were effective in improving specific discharge capacities. The specific discharge capacity increased from 75 mAh·g^-1 to 115 mAh·g^-1 at the rate of 1C. The stronger bond energy of Mn-O in the modified MnO₂ could suppress the volume expansion during the discharge process, which can maintain the structural stability of the manganese dioxide material.

Key words:

line-height: 150%">mso-bidi-font-size: 10.5pt">Manganese dioxide cathode material, Ag-TiO₂, modification, electrochemical performance